Research On AUV Formation Control Method Based On Leader-Follower

Autonomous Underwater Vehicle(AUV)is a kind of marine detector that can navigate autonomously.Since it has the characteristics of strong autonomy and high mobility,it has a wide range of applications in ocean observation,maritime rescue,range search,pipeline inspection and other fields.With the continuous deepening of ocean exploration,the multi-AUV system provides new solutions for ocean exploration tasks due to its good redundancy,coordination and efficiency when faced with complex underwater tasks.As one of the key technologies of multi-AUV systems,formation control technology has received extensive attentions from researchers of various countries.As we know,the formation control of multiple AUVs involves a wide range of problems,including formation algorithms,control,communication,planning,circuit design and other technical fields.Among them,the underwater formation application has two difficulties that must be faced:First,the particularity of underwater environment and the under-actuated characteristics of the AUV make common formation controllers of drones or land robots not suitable for AUVs.Second,the high latency and transmission error rate of underwater communications between AUVs will affect the formation effectiveness seriously.Due to these problems,this article has conducted an in-depth study on AUV formation control.According to the actual formation model,a kinematics mathematical model is established for single AUV and multiple AUV systems.Based on Lyapunov’s theory and idea of backstepping control,a leader-follower control strategy based on geometric mathematical model is proposed.It is proved that the AUV system can achieve a stable state under the action of this control strategy.Aiming at the delay problem of underwater communication,a communication delay compensation method is designed to reduce the error caused by communication delay.Combined with the commonly used PID control method in the engineering field,a complete formation control scheme is simulated with Matlab platform.In order to verify the actual effect of proposed formation algorithm,three AUVs are designed in this paper,and detailed software and hardware implementation schemes are proposed.The AUV uses a pressure sensor to obtain the pressure value and calculates its depth data,uses a satellite/inertial integrated navigation system to obtain position and attitude information,exchanges data with other AUVs through underwater acoustic communication,and implements a formation strategy in an environment based on the ROS software architecture.Finally,three AUVs are tested in the formation lake.The experimental results show that multiple AUVs can complete the formation switching and formation maintenance between the triangle and the inline shape using formation control algorithm proposed in this paper,so it meets the needs of formation control.